We often hear about noise-canceling headphones. So, what are the current active noise reduction in the headset market?
Mainly ANC, ENC noise reduction technology. The following briefly introduces the difference between these two noise reduction modes:
1. ANC noise reduction (Active Noise Control, active noise reduction)
The working principle of ANC noise reduction is that the microphone collects external environmental noise, and then the system transforms it into an inverted sound wave and adds it to the speaker. The final sound heard by the human ear is: environmental noise + inverted environmental noise, two kinds of noise superimposed, So as to realize the reduction of sensory noise, and the beneficiary is oneself. ANC active noise reduction can be divided into feedforward active noise reduction (with more headphone applications), feedback active noise reduction, and hybrid active noise reduction. Feedback type is easy to cause howling.
The Airpods pro released by Apple in October 2019 is a headset that supports ANC. It is claimed to solve two difficulties well. One is to solve the space occupation problem through SIP encapsulation, and the other is to make a ventilation system to solve the problem of the pressure difference between the inside and outside of the ear and ensure the wearing comfort. The specific experience is yet to be verified later.
At present, Android Bluetooth platforms have begun to support ANC. The key is to see whether headset manufacturers can overcome engineering problems and truly improve the noise reduction experience.
2. ENC (Environmental Noise Cancellation, environmental noise reduction technology)
ENC uses a dual-microphone array to accurately calculate the direction of the caller’s speech, which protects the target voice in the main direction while removing various interference noises in the environment. ENC technology can effectively suppress 90% of the reverse environmental noise, thereby reducing the environmental noise up to 35dB or more, allowing game players to communicate more freely.
The current ENC solutions are mainly Airpods and Google’s pixel buds, and they all use STMicroelectronics’ solutions. The ENC solution requires relatively large algorithm development work and will also increase the power consumption of the whole system. Therefore, it has not yet been popularized in Android brand TWS headsets.